Can NOT preview or publish my blog

I have tried to preview and publish my blog several times today. Each time I get an "error on page" notation in the lower left. It will Not launch the preview and I can NOT publish. I have tried to clear cookies and refreshing page. I do not know what settings to change in the browser. I did turn off pop up blocker but that did not help. I know I have been getting internet browser update requests but I am on XP and not sure what to do. Please help.

tried that, still get error on page. FYI- I have posted over 400 posts and noticed over past few days I had to "click" a couple of times sometimes to get preview to open. Now just get "error on page" if I try to preview or publish. I changed toeh third party cookies but didn't restart computer. I have just tried to preview or post but same results.

Thanks timethief, I did finally preview and post...not sure which trick did it but I did enable third party, removed a junk search bar I think had been loaded through some garbage ilivid put on my computer a few weeks back. I did all turn off add-ons...not sure which worked but posted for the day:) Will see what tomorrow brings and I appreciate you being there!

I've had the same problem for a few days. When trying to write a new post from the main page (the one I get to when I log in), there's no preview button. I'm not sure if there never was one there. In any case, if I go to Dashboard and write a new post from there, I get to preview it.